."descend to altitude 4000 feet QNH 1012 millibars and turn right heading 340 degrees
"Altitude" is inserted between the "to" and the "4,000" to reinforce that you are being cleared to 4,000ft, not "two four thousand" (i.e. 24,000).
"Millibars" is so our Yankee friends don't set inches of mercury. I.e. QNH nine nine two (MB) is easily mistaken for 29.92 (inches).
"340
degrees reinforces that the 340 mentioned is not a FL.
There's method in the madness!